So I have a direct drive trainer and picked up a spare frame for a dedicated trainer bike. I had enough parts to just about have it ready to go, except a rear derailleur. I only need it for ERG, so I don’t need to shift. Options I can think of are:
- buy a cheap mechanical RD and use an old cable to set it in the gear I want.
- buy a single speed chain tensioner
- maybe this? (https://bike.shimano.com/en-US/product/component/alfine-s7000s700/CT-S500.html) not sure it will work. I have a Wolf Tooth road link laying around I could throw on to clear a bigger gear.
- other options I’m not thinking of?
Edit: or just wrap the chain on the gear I want and try to get the length close. I’m not shifting and the bike isn’t moving. Should work?